We test two hypotheses, based on sexual selection theory, about gender differences in costly social interactions. Differential selectivity states that women invest less than men in interactions with new individuals. Differential opportunism states that women’s investment in social interactions...

This paper examines how networks of professional contacts contribute to the development of the careers of executives of North American and European companies. We build a dynamic model of career progression in which career moves may both depend upon existing networks and contribute to the...